mobile

Hi,
I have a weird question. I even don't know whether I'm posting in the correct section or not. Admins, please move this question to the correct section.

In the US, most of the cell phone sales are through Carriers. But its not in the developing countries. Its a more prepaid market.
That means, we go to Walmart, and buy grocery and similarly, we buy cell phones and recharge cards and refill our account.
Mostly it is prepaid market. But in the US, its mostly postpaid market and contracts.


Is there any way, I can get some details, about the carriers, on the whole, - not of each individual carriers, source of income.
Example : Lets say 100 people need cell phones. How many are walking into any of the carrier's stores and signing up a contract and how many are going online on amazon or ebay or craigslist and buying their cell phones and plans online?? and how many are going in for walmart, target, bestbuy, frys, and buying a cell phone and plans available there.

Does a report of this nature exist?? I'm not sure.
I'm trying to find myself online, but cannot find one.

Thanks a lot for the help. Its for one of my school work's project. I need to develop more on that, with graphs, pie charts, and strategies/suggestions.
Thank You and peace.